The Nuclear Regulatory Commission's inspector general points to significant flaws in reporting of equipment problems at U.S. nuclear plants. There is ambiguity in the reporting requirements, with one section Part 21 of the reporting law requiring reporting defects that can cause a loss of safety functions, and another section requiring reporting only the actual loss of safety functions. As a result 28% of the nuclear plants are not reporting safety defects in equipmment unless this leads to an actual breakdown. This represents an unacceptable level of risk for nuclear plant operations, and the inspector general calls for increasing the margin of safety. In fact the NRC is aware of these lapses in reporting since 2009. NRC has identified 24 such instances between Dec 2009 and Sept 2010, and yet no penalties have been assessed or corrective action taken to make the law clear about the reporting requirements. The lack of a good reporting system complicates things further, because early indentification of defects and defect resolution for equipment problems is critical to effective quality assurance for nuclear operators. Safety defect spotted at one plant could come up in other plants. For this reason the Inspector General's report calls this "a substantial safety hazard."...